Abstract: The determination of dopamine at the active carbon modified carbon paste electrode (ACMCPE) via cyclic voltammetry and differential pulse voltammetry was studied. Owing to the special quality of abundant surface functional groups, a well quasi reversible redox peak appeared between 0.37 V and 0.04 V when ACMCPE was scanning in pH=7.63 phosphate buffer solution (PBS) containing dopamine at a sc an rate of 100　mV/s. There were three linear calibrate curves of dopamine （DA） in a conc entration range of 2×10^－７~1×10^－３ mol/L for different preconcen tration time. The determination limit at Signal/Noise=3 was 7.5×10^－８ mol/L. Ascorbic acid (AA) as the familiar interfering compound had little interference in the determination of dopamine.

Key words: rice hull, active carbon, differential pulse voltammet ry, dopamine